【摘要】 目的通过研究Ⅰ组代谢型谷氨酸受体(mGluRs)mGluR1及mGluR5在帕金森病(PD)大鼠纹状体神经元细胞膜蛋白和总蛋白的表达变化,探讨Ⅰ组mGluRs在纹状体神经元细胞膜/细胞内分布改变是否参与PD的发病机制。方法选取雄性SD大鼠20只,随机分为PD组[以6-羟多巴(6-OHDA)单侧脑内注射法制备;n=10]和Sham组(操作方法相同,以等量生理盐水代替6-OHDA;n=10)。采用Western blot方法检测两组大鼠纹状体损伤侧和非损伤侧mGluR1及mGluR5总蛋白和膜蛋白水平变化,以及其下游重要信号分子细胞外信号调节激酶1/2(ERK1/2)和c-Jun氨基末端激酶(JNK)磷酸化水平,比较两组损伤侧与非损伤侧上述各指标表达情况。结果 Western blot结果显示Sham组非损伤侧、Sham组损伤侧、PD组非损伤测及PD组损伤侧mGluR1总蛋白水平差异无统计学意义(F=0.329,P=0.805),PD组损伤侧mGluR1膜蛋白表达较PD组非损伤侧、Sham组损伤侧和Sham组非损伤侧均明显增高(均P<0.05);PD组损伤侧mGluR5总蛋白水平和膜蛋白水平均较相应PD组非损伤侧、Sham组损伤侧及Sham组非损伤侧均明显增高(均P<0.05);与PD组非损伤侧、Sham组损伤侧和Sham组非损伤侧比较,PD组损伤侧ERK1/2磷酸化水平明显降低,JNK磷酸化水平明显升高(均P<0.05);上述指标在PD组非损伤侧、Sham组损伤侧和Sham组非损伤侧之间两两比较差异均无统计学意义(均P>0.05)。结论 PD大鼠纹状体Ⅰ组mGluRs的变化以膜蛋白的表达异常增加为主,可能与其在细胞膜/细胞内分布的改变相关,并且改变可能影响下游ERK1/2和JNK磷酸化水平,推测纹状体神经元Ⅰ组mGluRs分布的变化可能与PD发病机制相关。更多还原

【Abstract】 Objective To explore whether the change of the striatal neuron membrane/intracellular distribution of group Ⅰ metabotropic glutamate receptors(mGluRs)is involved in the pathogenesis of Parkinson’s disease(PD),by studying the alternation of mGluRs membrane-protein and total protein expression in the striatum of PD rat model.Methods Twenty male SD rats were randomly divided into a PD group(prepared by unilateral intracerebral injection of 6-OHDA;n = 10) and a sham group(prepared by the same method, with the same amount of saline instead of 6-OHDA;n = 10).Western blot method was used to detect changes of the total protein and membrane protein expression of mGluR1 and mGluR5,in the lesion and non-lesion sides of the two groups, as well as the phosphorylation levels of extracellular signal-regulated kinases 1/2(ERK1/2) and c-Jun N-terminal kinase(JNK) which are important signal molecules downstream of mGluR1 and mGluR5.The expressions of these proteins in lesion and non-lesion sides were compared between the two groups.Results The data showed that the total expression of mGluR1 in non-lesion sides of the sham group, lesion side of the sham group, non-lesion side of the PD group and the lesion side of the PD group were not significantly different(F=0.329, P=0.805).The membrane-expression of mGluR1 in the lesion side of the PD group was significantly higher than the non-lesion side of the PD group, lesion side of the sham group, and non-lesion side of the sham group(P<0.05,respectively).Both total expression and membrane-expression of mGluR5 in the lesion side of the PD group were significantly higher than those in the non-lesion side, lesion side of the sham group, and non-lesion side of the sham group(P<0.05,respectively).Compared with unlesion side of the PD group, lesion side of the sham group, and non-lesion side of the sham group, the phosphorylation level of ERK1/2 in the lesion side of the PD group was significantly decreased, while the phosphorylation level of JNK was significantly increased(P<0.05,respectively).Conclusions The changes of group Ⅰ mGluRs in the striatum of PD rat model are mainly the significant increase of its membrane protein expression, which may be related to the changes of its cell membrane/intracellular distribution.These changes might affect the phosphorylation levels of downstream ERK1/2 and JNK.These data suggest that the changes of striatal subcellular distribution of group Ⅰ mGluRs may be involved in the pathogenesis of PD.更多还原